Associations of the MTHFR rs1801133 polymorphism with coronary artery disease and lipid levels: a systematic review and updated meta-analysis

Homocysteine concentration in coronary artery disease and severity of coronary lesions

Our previous study reckons that the impact of the rs1801133 variant of 5,10-methylenetetrahydrofolate reductase (MTHFR) on coronary artery disease (CAD) is possibly mediated by cardiometabolic disorder. This study is performed to verify this hypothesis. Four hundred and thirty CAD patients and 216 CAD-free individuals were enrolled in this case-control study. The rs1801133 variant was genotyped by PCR-RFLP. Severity of coronary lesions was evaluated by number of stenotic coronary vessels and extent of coronary stenosis. The rs1801133 T allele significantly increased homocysteine levels in patients with CAD and CAD-free individuals. Individuals with the T allele of rs1801133 had an increased risk of developing CAD. In contrast, individuals with the TT genotype of rs1801133 were at high risk of multiple vessel lesions. The carriers of CT genotype had higher levels of systolic blood pressure (SBP), low-density lipoprotein cholesterol (LDL-C), and high-sensitivity C-reactive protein (hs-CRP), and lower levels of apolipoprotein A1 (APOA1) than those with CC genotype in male patients with CAD. The receiver operating characteristic (ROC) curve and precision-recall (PR) curve indicated that hyperhomocysteinemia was sensitive to predict the severity of CAD. Multivariate logistic regression revealed that homocysteine, rs1801133, age, smoking, weight, body mass index (BMI), lipoprotein(a) [Lp(a)], and hs-CRP were independent risk factors for CAD. The increased risk of CAD and severity of coronary lesions associated with rs1801133 in the Chinese Han population were attributed, at least partly, to high homocysteine levels. Hyperhomocysteinemia had a high predictive value for severe CAD or multiple vessel lesions.

MTHFR C677T, hyperhomocysteinemia, and their interactions with traditional risk factors in early neurological deterioration in Chinese patients with ischemic stroke

Objective

This study aimed to investigate the relationship between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and early neurological deterioration (END) in patients with acute ischemic stroke (AIS) and any possible interactions between specific MTHFR alleles and traditional risk factors among a Han Chinese cohort.

Methods

434 AIS patients were consecutively recruited between January 2017 and June 2019, including 129 END and 305 non-END cases. A candidate gene association study design was used to analyze the association between MTHFR gene polymorphism and END risk. The polymerase chain reaction-restriction fragment length polymorphism (RFLP) method was employed to genotype the MTHFR C677T polymorphism. The interactional analyses were performed using the multifactor dimensionality reduction test.

Results

Hyperglycemia (odds ratio [OR]: 2.410, 95 % confidence interval [CI]: 1.436-4.046, p = 0.001), neurological function impairment (NIHSS score >5) (OR: 2.158, 95%CI: 1.337-3.484, p = 0.002) on admission, and hyperhomocysteinemia (HHcy) (OR: 2.570, 95%CI: 1.229-5.376, p = 0.012) were independently associated with END. The TT genotype (OR: 1.710, 95%CI: 1.021-2.863, p = 0.043) and T allele (OR: 1.710, 95%CI: 1.021-2.863, p = 0.043) of this C677T polymorphism were associated with susceptibility to END, and the TT genotype was more common in the subjects with HHcy (OR: 2.525, 95%CI: 1.111-5.739, P = 0.023). In addition, we also found interactions for END risk between the C677T polymorphism and traditional risk factors for END, including: hyperglycemia on admission, drinking, and moderate to severe neurological deficits (OR 1.237, 95 % CI 0.227-6.734), although the results were not statistically significant (p = 0.806).

Conclusions

Our results show a possible association between MTHFR C677T polymorphism and gene-environment interactions with END susceptibility in a Han Chinese cohort.

Association between Psoriasis and MTHFR polymorphisms: a systematic review and meta-analysis

Methylenetetrahydrofolate reductase (MTHFR) is key to the metabolism of folic acid, with loss of function mutations resulting in elevated homocysteine levels, a known risk factor for cardiovascular disease. Psoriasis patients may demonstrate hyperhomocysteinemia. To assess for the association between psoriasis and MTHFR C677T and A1298C polymorphisms. A systematic literature search was conducted in MEDLINE, Embase, Cochrane CENTRAL, and Web of Science. Case reports, case-control, cohort, and cross-sectional studies with full-text availability in English were considered. Meta-analysis was conducted with pooled ORs calculated via the random effects model (I2 > 50%). Of 917 records identified, 10 studies were selected for review of 1965 psoriasis patients and 2030 controls. Meta-analysis demonstrated that for MTHFR C677T, there were positive associations between psoriasis and the allele contrast model (C vs T, pooled OR = 1.69, 95% CI = 1.10-2.59), the additive model (CC vs TT, pooled OR = 2.44, 95% CI = 1.06-5.60), the dominant model (CC vs CT + TT, pooled OR = 1.77, 95% CI = 1.06-2.98), and the recessive model (CC + CT vs TT, pooled OR = 2.08, 95% CI = 1.05-4.13). For MTHFR A1298C, there were positive associations between psoriasis and the allele contrast model (A vs C, pooled OR = 3.57, 95% CI = 1.19-10.68), the dominant model (AA vs AC + CC, pooled OR = 4.44, 95% CI = 1.12-17.66), and the overdominant model (AC vs AA + CC, pooled OR = 0.26, 95% CI = 0.07-0.91). There may be a link between the C677T and A1298C polymorphisms with psoriasis diagnosis.

ALDH2 rs671 and MTHFR rs1801133 polymorphisms are risk factors for arteriosclerosis in multiple arteries

BACKGROUND

Arteriosclerosis in multiple arteries has long been associated with heightened cardiovascular risk. Acetaldehyde dehydrogenase 2 (ALDH2) and methylenetetrahydrofolate reductase (MTHFR) play an important role in the pathogenesis of arteriosclerosis by participating in the oxidation and reduction reactions in vascular endothelial cells. The purpose was to investigate the relationship of ALDH2 and MTHFR gene polymorphisms with arteriosclerosis in multiple arteries.

METHODS

410 patients with arteriosclerosis in single artery and 472 patients with arteriosclerosis in multiple arteries were included. The relationship between ALDH2 rs671 and MTHFR rs1801133 polymorphisms and arteriosclerosis in single artery and arteriosclerosis in multiple arteries was analyzed.

RESULTS

The proportion of ALDH2 rs671 A allele (35.6% vs. 30.9%, P = 0.038) and MTHFR rs1801133 T allele (32.6% vs. 27.1%, P = 0.012) in patients with arteriosclerosis in multiple arteries was significantly higher than that in arteriosclerosis in single artery, respectively. The proportion of history of alcohol consumption in patients with ALDH2 rs671 G/G genotype was higher than those in ALDH2 rs671 G/A genotype and A/A genotype (P < 0.001). The results of logistic regression analysis indicated that ALDH2 rs671 A/A genotype (A/A vs. G/G: OR 1.996, 95% CI: 1.258-3.166, P = 0.003) and MTHFR rs1801133 T/T genotype (T/T vs. C/C: OR 1.943, 95% CI: 1.179-3.203, P = 0.009) may be independent risk factors for arteriosclerosis in multiple arteries (adjusted for age, sex, smoking, drinking, hypertension, and diabetes).

CONCLUSIONS

ALDH2 rs671 A/A and MTHFR rs1801133 T/T genotypes may be independent risk factors for arteriosclerosis in multiple arteries.

Methylenetetrahydrofolate reductase deficiency and high-dose FA supplementation disrupt embryonic development of energy balance and metabolic homeostasis in zebrafish

Folic acid (synthetic folate, FA) is consumed in excess in North America and may interact with common pathogenic variants in methylenetetrahydrofolate reductase (MTHFR); the most prevalent inborn error of folate metabolism with wide-ranging obesity-related comorbidities. While preclinical murine models have been valuable to inform on diet-gene interactions, a recent Folate Expert panel has encouraged validation of new animal models. In this study, we characterized a novel zebrafish model of mthfr deficiency and evaluated the effects of genetic loss of mthfr function and FA supplementation during embryonic development on energy homeostasis and metabolism. mthfr-deficient zebrafish were generated using CRISPR mutagenesis and supplemented with no FA (control, 0FA) or 100 μm FA (100FA) throughout embryonic development (0-5 days postfertilization). We show that the genetic loss of mthfr function in zebrafish recapitulates key biochemical hallmarks reported in MTHFR deficiency in humans and leads to greater lipid accumulation and aberrant cholesterol metabolism as reported in the Mthfr murine model. In mthfr-deficient zebrafish, energy homeostasis was also impaired as indicated by altered food intake, reduced metabolic rate and lower expression of central energy-regulatory genes. Microglia abundance, involved in healthy neuronal development, was also reduced. FA supplementation to control zebrafish mimicked many of the adverse effects of mthfr deficiency, some of which were also exacerbated in mthfr-deficient zebrafish. Together, these findings support the translatability of the mthfr-deficient zebrafish as a preclinical model in folate research.

Impact of genetic information on coronary disease risk in Madeira: The GENEMACOR study

INTRODUCTION

Coronary artery disease (CAD), characterized by an atherogenic process in the coronary arteries, is one of the leading causes of death in Madeira. The GENEMACOR (GENEs in MAdeira and CORonary Disease) study sought to investigate the main risk factors - environmental and genetic - and estimate whether a genetic risk score (GRS) improves CAD prediction, discrimination and reclassification.

METHODS

Traditional risk factors and 33 CAD genetic variants were considered in a case-control study with 3139 individuals (1723 patients and 1416 controls). The multivariate analysis assessed the likelihood of CAD. A multiplicative GRS (mGRS) was created, and two models (with and without mGRS) were prepared. Two areas under receiver operating characteristic curve (area under curve (AUC)) were analyzed and compared to discriminate CAD likelihood. Net reclassification improvement (NRI) and integrated discrimination index (IDI) were used to reclassify the population.

RESULTS

All traditional risk factors were strong and independent predictors of CAD, with smoking being the most significant (OR 3.25; p<0.0001). LPA rs3798220 showed a higher CAD likelihood (odds ratio 1.45; p<0.0001). Individuals in the fourth mGRS quartile had an increased CAD probability of 136% (p<0.0001). A traditional risk factor-based model estimated an AUC of 0.73, rising to 0.75 after mGRS inclusion (p<0.0001), revealing a better fit. Continuous NRI better reclassified 28.1% of the population, and categorical NRI mainly improved the reclassification of the intermediate risk group.

CONCLUSIONS

CAD likelihood was influenced by traditional risk factors and genetic variants. Incorporating GRS into the traditional model improved CAD predictive capacity, discrimination and reclassification. These approaches may provide helpful diagnostic and therapeutic advances, especially in the intermediate risk group.

Association of endometriosis with cardiovascular disease: Genetic aspects (Review)

Cardiovascular disease (CVD) comprises a broad spectrum of pathological conditions that affect the heart or blood vessels, including sequelae that arise from damaged vasculature in other organs of the body, such as the brain, kidneys or eyes. Atherosclerosis is a chronic inflammatory disease of the arterial intima and is the primary cause of coronary artery disease, peripheral vascular disease, heart attack, stroke and renal pathology. It represents a leading cause of mortality worldwide and the loss of human productivity that is marked by an altered immune response. Endometriosis is a heritable, heterogeneous, common gynecological condition influenced by multiple genetic, epigenetic and environmental factors, affecting up to 10% of the female population of childbearing age, causing pain and infertility; it is characterized by the ectopic growth of endometrial tissue outside the uterine cavity. Of note, epidemiological data obtained thus far have suggested a link between endometriosis and the risk of developing CVD. The similarities observed in specific molecular and cellular pathways of endometriosis and CVD may be partially explained by a shared genetic background. The present review presents and discusses the shared genetic factors which have been reported to be associated with the development of both disorders.

Mild methylenetetrahydrofolate reductase deficiency accelerates liver triacylglycerol and uric acid accumulation in fructose-fed mice

A genetic predisposition to hepatic steatosis may be associated with dietary patterns. We hypothesized that a common variant in human methylenetetrahydrofolate reductase (MTHFR 677C→T) was previously associated with an increased risk of nonalcoholic fatty liver disease (NAFLD). In this study, we investigated the relationship between the human MTHFR polymorphism and NAFLD using fructose-fed male C57BL/6 Mthfr^+/+ and Mthfr^+/- mice, a model for the human gene variant. Mice were fed an 8% fructose solution for 12 weeks. Mthfr^+/- mice had significantly increased abdominal fat mass and hepatic triglyceride (TG) but displayed a similar liver mass when compared with Mthfr^+/+ mice. Liver morphology showed that mild MTHFR deficiency induced liver lipid droplet deposition and inflammatory cell infiltration, suggesting accelerated lipid accumulation in the liver. Moreover, mild MTHFR deficiency increased hepatic xanthine oxidase activity and uric acid accumulation. Using untargeted lipidomics, we identified 116 differentially expressed lipids species in the liver of Mthfr^+/- mice when compared with Mthfr^+/+ animals. The most significant lipid increase was observed in 47 TGs, followed by 33 phosphatidylcholines in Mthfr^+/- mice liver. When compared with Mthfr^+/+ liver, 9 TGs were dramatically decreased in Mthfr^+/- liver. These changes were associated with upregulated gene expressions related to triglyceride synthesis and storage. Thus, Mthfr^+/- mice developed NAFLD disease. These findings suggested the Mthfr variant may be at an increased risk of liver steatosis on a fructose solution diet.

The Effect of 3-Week Betaine Supplementation on Blood Biomarkers of Cardiometabolic Health in Young Physically Active Males

Betaine (BET) supplementation decreases homocysteine concentration in plasma, but it may also have an adverse effect on health by increasing blood lipid concentrations, at least in overweight and obese individuals. The aim of this study was to evaluate the effect of BET supplementation on the lipid profile and concentrations of homocysteine, inflammatory cytokines, and liver enzymes in physically active, healthy males. This was a randomized, placebo (PL)-controlled, double-blinded, crossover trial. BET (2.5 or 5.0 g/d) was administered for 21 days. Before and after supplementation with BET or PL, anthropometric measurements and blood were collected in a fasted state. Our results show that BET supplementation significantly decreased homocysteine concentration (from 17.1 ± 4.0 μmol/L before BET to 15.6 ± 3.5 μmol/L after BET, p = 0.009, η² = 0.164). However, the intervention had no effect on total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triacylglycerol, interleukins 1β and 6, and tumour necrosis factor α concentrations, or alanine and aspartate activities. In addition, there were no interactions between the MTHFR genotype and BET dose. In conclusion, BET supplementation may be beneficial for homocysteine concentration in healthy, physically active males, with no detrimental effect on lipid profile.

A systematic review and meta-analysis expounding the relationship between methylene tetrahydrofolate reductase gene polymorphism and the risk of intracerebral hemorrhage among populations

Background: The relationship between methylenetetrahydrofolate reductase (MTHFR) gene C677T and A1298C polymorphism with the risk of intracerebral hemorrhage (ICH) has remained to be controversial in recent years. This meta-analysis is aimed to confirm the association of these.

Methods: Systematically searching the related studies from the PubMed, Embase, Cochrane Library, China national knowledge internet database from 1 January 1990 to 1 June 2022. The odd ratio (ORs) and 95% confidence interval (CIs) of gene-disease correlation in various gene models were calculated by fixed or random effect model of meta-analysis. We included 20 case-control studies in this meta-analysis with a total of 1,989 ICH patients and 4,032 health controls originated from Asian, Caucasian, and African populations.

Results: The statistical analysis demonstrated the association of MTHFR C677T gene polymorphism with ICH in allele model [OR_{T VS. C} = 1.20 (95%CI: 1.06–1.36)]; homozygote model [OR _{TT VS. CC} = 1.50 (95%CI: 1.20–1.88)]; dominant model [OR _{CT+ TT VS. CC} = 1.23 (95%CI: 1.03–1.48)] and recessive model [OR_{TT VS. CT+CC} = 1.37 (95%CI: 1.17–1.60)]. Besides, we also found the relationship of MTHFR C677T gene polymorphism with Asian in four comparison model (OR_{T VS. C} = 1.19.95%CI:1.09–1.37, OR_{TT VS. CC} = 1.46.95%CI: 1.15–1.85, OR _{CT+ TT VS. CC} = 1.25.95%CI: 1.01–1.54, OR_{TT VS. CT+CC} = 1.34.95%CI: 1.54–1.17) and Caucasian in four comparison model (OR_{T VS. C} = 1.90.95%CI: 1.22–2.97, OR_{TT VS. CC} = 2.67.95%CI: 1.42–5.00, OR _{CT+ TT VS. CC} = 1.56.95%CI: 1.05–2.32, OR_{TT VS. CT+CC} = 2.25.95%CI: 1.46–4.00). But no statistically significant correlation between A1298C polymorphism and the occurrence of ICH was detected in four studies.

Conclusion: MTHFR C677T gene polymorphism increases the risk of ICH in Asian and Caucasian populations but has no impact on the incidence in African communities. More importantly, the risk of ICH increases in TT genotype individuals in comparison to CT and CC genotype individuals in Asian and Caucasian populations.

Associations of Two Common Polymorphisms in MTHFR Gene with Blood Lipids and Therapeutic Efficacy of Simvastatin

BACKGROUND AND PURPOSE

Cardio-cerebrovascular disease is an important public health challenge worldwide, and its complex etiology has not been elucidated fully. The study was to investigate the relationship between two common polymorphisms C677T and A1298C in the methylenetetrahydrofolate reductase (MTHFR) gene, baseline lipids and the lipid-lowering efficacy of simvastatin in a Chinese hyperlipidemic population.

METHODS

All participants were recruited from Anhui, China. By the extreme sampling method, we selected subjects with low response (n=108) and high response (n=106) based on their adjusted lipid-lowering response to simvastatin administrated for 8 consecutive weeks. Both MTHFR C677T and A1298C loci were genotyped by MALDI-TOF MS platform. Serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels were measured at baseline and after 8 weeks of oral 20 mg/d tablet of simvastatin.

RESULTS

Patients with the 677TT genotype had significantly higher baseline TC, HDL-C, and change in HDL-C (ΔHDL-C) levels after treatment than those with 677CC+CT genotypes (β = 0.207, P = 0.045; β = 0.182, P = 0.026; and β = 0.16, P = 0.002, respectively). Patients with 1298AC+CC genotypes had significantly higher baseline LDL-C and change in LDL-C (ΔLDL-C) levels (β = 0.276, P =0.043; β = 0.359, P = 0.025, respectively) than those with 1298AA genotype. We found statistical interactions between the two SNPs in association with baseline HDL-C (P for interaction = 0.034), TC (P for interaction = 0.069), and TG (P for interaction = 0.034). Baseline TC (P = 0.027) and HDL-C (P = 0.046) and change in HDL-C (P = 0.019) were different among those with the MTHFR A-T haplotype compared with A-C.

CONCLUSIONS

Our major findings suggest that both MTHFR C677T and A1298C polymorphisms could be important genetic determinants of lipid traits and drug efficacy of simvastatin. This will contribute to a better understanding of strategies for personalized medication in Chinese patients with dyslipidemia.

Osteoprotegerin and MTHFR gene variations in rheumatoid arthritis: association with disease susceptibility and markers of subclinical atherosclerosis

We aimed to explore whether the rs2073618 variant (G1181C) of the osteoprotegerin (OPG) gene and the methylenetetrahydrofolate reductase (MTHFR) rs1801131 (A1298AC) and rs1801133 (C677T) gene polymorphisms contribute to rheumatoid arthritis (RA) susceptibility and RA related subclinical atherosclerosis. Overall 283 RA patients and 595 healthy controls (HC) were genotyped for common variants of the OPG and MTHFR genes using PCR based assays. Clinical and laboratory parameters were recorded following thorough chart review. Surrogate markers of subclinical atherosclerosis (Carotid/Femoral intima media thickness/plaque formation) along with traditional risk factors for atherosclerosis were assessed in all RA patients and 280HC. Increased prevalence of the CC genotype of the rs2073618 variant was detected in RA patients vs HC (42.4% vs. 33%, p-value: 0.04). RA patients with high serum titers of rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP) antibodies displayed increased prevalence of the CC genotype of the rs2073618 variant of the OPG gene compared to HC (48.6% and 47.5 vs 33.3%, p-values: 0.0029and 0.0077 respectively). Of interest, this genotype turned to be associated with higher carotid IMT scores (0.872 ± 0.264 vs 0.816 ± 0.284, p-value: 0.01) and marginally with higher rates of carotid plaque formation (66% vs 54.1%, p = 0.06). The MTHFR 1298CC genotype was more prevalent only in the anti-CCP positive group compared to HC, with no associations detected with markers of subclinical atherosclerosis, following adjustment for traditional cardiovascular (CVD) risk factors. Reduced rates of carotid/femoral plaque formation were detected among RA patients harboring the MTHFR TT genotype (52.4 vs 72.7, p-value: 0.009, respectively). This association remained significant following adjustment for classical CVD risk factors (OR [95% CI 0.364 [0.173–0.765], p-value: 0.008). Genetic variations of the osteoprotegerin and MTHFR genes seem to increase susceptibility for seropositive RA and potentially contribute to subclinical atherosclerosis linked to RA. Larger studies are needed to confirm these findings.

Association of Fetal MTHFR C677T Polymorphism with Susceptibility to Neural Tube Defects: A Systematic Review and Update Meta-Analysis

Background MTHFR gene may be a key epigenetic regulation-related factor crucial during embryogenesis. We performed a meta-analysis to determine the association of fetal MTHFR C677T polymorphism with neural tube defects (NTDs).Methods A comprehensive literature search of the PubMed, Embase, and CNKI database was performed up to April 10, 2020.Results A total of 19 case-control studies with 2,228 NTDs cases and 4,220 controls were identified. Pooled data revealed that the fetal MTHFR C677T polymorphism was significantly highly correlated with development of NTDs in the overall population. Stratified analysis showed a significant association among Caucasians and Asians, but not in mixed populations. There was a significant association between the MTHFR C677T polymorphism and spina bifida risk. No publication bias was found under any genetic model.Conclusions Our pooled data support the fetal MTHFR C677T polymorphism association with risk of NTDs, especially among Caucasians and Asians.

Association of the methylenetetrahydrofolate reductase (MTHFR) gene variant C677T with serum homocysteine levels and the severity of ischaemic stroke: a case-control study in the southwest of China

OBJECTIVE

To determine whether the methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism is linked to the risk of ischaemic stroke and circulating homocysteine (Hcy) levels in a Chinese population.

METHODS

This case-control study recruited angiogram-diagnosed patients with ischaemic stroke and healthy control subjects. The plasma Hcy concentrations were measured and the MTHFR C677T gene polymorphism was genotyped. The National Institutes of Health Stroke Scale (NIHSS) was used to assess the severity of the ischaemic stroke.

RESULTS

This study recruited 198 patients with ischaemic stroke and 168 controls. The TT genotype conferred a higher risk for ischaemic stroke than the CC genotype (odds ratio of 3.563; 95% confidence interval [CI] 1.412, 4.350). The T allele was the predisposing allele for ischaemic stroke. Hcy had an area under the receiver operating characteristic (ROC) curve of 0.624 (95% CI 0.530, 0.758). The ROC for Hcy demonstrated its usefulness in predicting ischaemic stroke. Hcy levels were not associated with ischaemic stroke severity as measured by the NIHSS.

CONCLUSION

The MTHFR C677T gene polymorphism affects circulating Hcy levels. The MTHFR C677T gene polymorphism and hyperhomocysteinaemia may play important roles in predicting the risk of ischaemic stroke.

Association between MTHFR C677T polymorphism and risk of coronary artery disease in the Chinese population: meta-analysis

BACKGROUND

Previous studies have investigated the close association between the MTHFR C677T polymorphism and the risk of coronary heart disease (CAD) in the Chinese population. However, the results remain inconclusive. Therefore, this meta-analysis was performed to derive a more precise estimate of these associations.

METHODS

Odds ratios (OR) with 95% confidence intervals (CI) were used to assess the relationship between the MTHFR C677T polymorphism and the risk of CAD. Studies were identified by searching the literature for articles published before 2017.

RESULTS

A total of 39 studies comprising 12,101 individuals (6117 cases and 5984 controls) were included. For the allelic model T vs. C, the pooled OR was 1.43 (95% CI: 1.30-1.57, p < 0.0001); for the recessive model TT vs. CC + TC, the pooled OR was 1.48 (95% CI: 1.29-1.70, p < 0.0001); for the dominant model TT + TC vs. CC, the pooled OR was 1.65 (95% CI: 1.43-1.89, p < 0.0001).

CONCLUSION

In the subgroup analysis of high-quality studies, an obvious association was observed between the MTHFR C677T polymorphism and CAD risk in the Chinese population.

Single Nucleotide Polymorphisms in Apolipoprotein B, Apolipoprotein E, and Methylenetetrahydrofolate Reductase Are Associated With Serum Lipid Levels in Northern Chilean Subjects. A Pilot Study

Characterization of allelic variants is relevant to demonstrate associations among genetic background and susceptibility to develop cardiovascular diseases, which are the main cause of death in Chile. Association of APOB, APOE, and MTHFR polymorphisms with higher lipid levels and the risk of developing hypertension and cardiovascular diseases have been described. Thus, the aim of this study was to assess genotype distribution and relative allelic frequency of ApoB rs693, ApoE rs7412, ApoE rs429358, MTHFR rs1801131, and MTHFR rs1801133 allelic variants and their effects on lipid profile in young healthy men and women from Northern Chile. A group of 193 healthy subjects were enrolled for this study. Genotyping of rs693 (APOB), rs7412 and rs429358 (APOE), and rs1801131 and rs1801133 (MTHFR) polymorphisms were performed by real time PCR. In addition, lipid profiles were determined and associated to genetic data. The genotype distribution was APOB rs693 (CC = 37%, CT = 41%, and TT = 22%), APOE rs7412/rs429358 (E4 = 0.06, E3 = 0.91, and E2 = 0.03), MTHFR rs1801131 (AA = 57%, AC = 30%, and CC = 13%), and MTHFR rs1801133 (CC = 20%, CT = 47%, and TT = 33%). The association of the genetic variants with plasma lipid levels showed that women, but not men, carrying APOB mutated allele (T) and Apo E4 allele presented lower values of total cholesterol when compared with C/C homozygous genotype or E3 allele, respectively (p < 0.05). In addition, a subgroup analysis revealed that ApoB C/C homozygous women exhibited higher values of HDL-C when compared with men carrying identical genotype (p < 0.01). On the other hand, women carrying E4 allele exhibited lower values of triglycerides when compared with male carrying identical genotype (p < 0.05). Finally, women carrying mutate allele (C) for MTHFR rs1801131 showed lower levels of triglycerides when compared with A/A homozygous genotype (p < 0.05) and lower levels of LDL-C for MTHFR rs1801133 in females carrying (T) allele when compared with males carrying identical genotype (p < 0.05). In summary, the present data showed that APOB, APOE, and MTHFR single nucleotide polymorphisms are associated to lipid levels in a gender-dependent manner among healthy subjects from Northern Chile, especially in women.

The combination of methylenehydrofolate reductase C677T polymorphism screening and gastrointestinal tumor markers detection may be an early screening method for gastrointestinal cancer related to helicobacter pylori infection

Methyltetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism, and its single nucleotide polymorphism (SNP) site C677T may be associated with gastrointestinal cancer. However, the relationship between MTHFR C677T polymorphism and gastrointestinal tumor markers carcinoma embryonic antigen (CEA), carbohydrate antigen 199 (CA199) and carbohydrate antigen 724 (CA724) in Helicobacter pylori (H. pylori) infection is not specified. This study aims to identify the association between MTHFR C677T polymorphism and gastrointestinal tumor markers (CEA, CA199 and CA724) in H. pylori infection. The relationship between MTHFR C677T polymorphism and gastrointestinal tumor markers in 58 patients with H. pylori infection and 94 non-infected patients was studied. We found that TT genotype was a susceptibility factor of H. pylori infection, which was also associated with increased CEA and CA724 levels. Moreover, there was a negative additive interaction between MTHFR gene C677T polymorphism and CEA levels in H.pylori infection. Meanwhile, there were significant differences in CEA levels between MTHFR C677T polymorphism and H.pylori infection. The presence of T allele led to a decrease in CEA levels when ¹³C urea breath test (¹³C-UBT) was positive, while the presence of T allele led to an increase in CEA levels when ¹³C-UBT was negative. Therefore, we suggest that healthy people should take MTHFR C677T polymorphism screening, combined with ¹³C-UBT and gastrointestinal tumor markers detection, which can screen out the susceptible population of H. pylori, and help to detect gastrointestinal cancer in the early stage.

Contrast-Induced Encephalopathy after Cerebral Angiogram: A Case Series and Review of Literature

Contrast-induced encephalopathy (CIE) is a rare complication that arises from exposure to iodinated contrast medium and can result in a range of symptoms, including cortical blindness, aphasia, focal neurological deficits, and altered mental status. We present 4 individual cases of CIE who presented with stroke-mimic symptoms following surgery with localized iodixanol or ioversol injection. We outline a clinical timeline of all patients, showing that CIE follows a general pattern of delayed onset, worsening symptomology, and ultimately full recovery. All patients received IV hydration, corticosteroids, or both as part of their treatment protocol.

Associations Among Methylene Tetrahydrofolate Reductase rs1801133 C677T Gene Variant, Food Groups, and Non-alcoholic Fatty Liver Disease Risk in the Chinese Population

Objectives

To investigate the associations among the methylene tetrahydrofolate reductase rs1801133 C677T gene variant, food groups, and the risk of non-alcoholic fatty liver disease in the Chinese population.

Methods

A study of gene polymorphism was conducted using the polymerase chain reaction method. A total of 4,049 adults participated in the study, and all underwent physical examination and genotyping. Participants filled out a dietary questionnaire to enable us to assess the frequency and quantity of food consumption.

Results

The important variables identified as risk factors of non-alcoholic fatty liver disease were age, smoking, sex, body mass index, hyperlipidemia, diabetes, and methylene tetrahydrofolate reductase genotype (T – allele carriers). The homocysteine content was higher in the non-alcoholic fatty liver disease group than in the control group, and was higher in the T- allele than C- allele carriers. The homocysteine content was the highest in the T- allele carriers. Additionally, certain food groups such as milk and beans were associated with a lower risk of non-alcoholic fatty liver disease. Food groups such as meat, were associated with a higher risk of non-alcoholic fatty liver disease. Fresh fruit and vegetables, salted and smoked foods, desserts, cereals, fish, and eggs were not associated with the risk of non-alcoholic fatty liver disease. However, the influence of salted and smoked foods on non-alcoholic fatty liver disease was different in the C-allele and T-allele carriers of methylene tetrahydrofolate reductase (CT + TT vs. CC, OR = 1.196, P = 0.041 for 1–4 times food per week, OR = 1.580, P = 0.004 for 5–7 times per week). Similarly, salted and smoked foods were also a risk factor for the development of non-alcoholic steatohepatitis in patients with non-alcoholic fatty liver disease.

Conclusion

This study found that the T-allele of the C677T variant of methylene tetrahydrofolate reductase was a risk factor for non-alcoholic fatty liver disease among Chinese people. These results can likely aid the development of novel approaches for managing non-alcoholic fatty liver disease risk.

Associations between MTHFR gene polymorphisms and the risk of intracranial hemorrhage: Evidence from a meta-analysis

INTRODUCTION

Previously, a number of genetic epidemiological studies have evaluated associations between MTHFR gene polymorphisms and the risk of intracranial hemorrhage (ICH), with controversial results. Accordingly, we carried out this meta-analysis to more conclusively evaluate associations between MTHFR gene polymorphisms and the risk of ICH.

METHODS

MEDLINE, EMBASE, Wanfang, VIP, and CNKI were searched comprehensively, and thirty-one genetic association studies were finally selected to be included in this meta-analysis.

RESULTS

Eight literatures (963 cases and 2,244 controls) assessed relationship between MTHFR rs1801131 (A1298C) polymorphism and the risk of ICH, and thirty-one literatures (3,679 cases and 9,067 controls) assessed relationship between MTHFR rs1801133 (C677T) polymorphism and the risk of ICH. We found that AA genotype of rs1801131 polymorphism was significantly associated with a decreased risk of intraventricular hemorrhage (IH) compared with AC/CC genotypes (OR = 0.63; p = .003), AC genotype was significantly associated with an increased risk of IH compared with AA/CC genotypes (OR = 1.55; p = .005), and A allele was significantly associated with a decreased risk of IH compared with C allele (OR = 0.75; p = .02). Additionally, CC genotype of rs1801133 polymorphism was significantly associated with a decreased risk of cerebral hemorrhage (CH) compared with CT/TT genotypes (OR = 0.75; p = .04), TT genotype was significantly associated with an increased risk of CH compared with CC/CT genotypes (OR = 1.27; p = .02), and C allele was significantly associated with a decreased risk of CH compared with T allele (OR = 0.85; p = .007).

CONCLUSIONS

This meta-analysis shows that rs1801131 polymorphism may influence the risk of IH, while rs1801133 polymorphism may influence the risk of CH.

Bioinformatics analysis identifies potential diagnostic signatures for coronary artery disease

Background

Coronary artery disease (CAD) is the leading cause of mortality worldwide. We aimed to screen out potential gene signatures and construct a diagnostic model for CAD.

Method

We downloaded two mRNA profiles, GSE66360 and GSE60993, and performed analyses of differential expression, gene ontology terms, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The STRING database was used to identify protein–protein interactions (PPI). PPI network visualization and screening out of key genes were performed using Cytoscape software. Finally, a diagnostic model was constructed.

Results

A total of 2127 differentially expressed genes (DEGs) were identified in GSE66360, and 527 DEGs in GSE60993. Of the 153 DEGs from both datasets that showed differential expression between CAD patients and controls, 471 biological process terms, 35 cellular component terms, 17 molecular function terms, and 49 KEGG pathways were significantly enriched. The top 20 key genes in the PPI network were identified, and a diagnostic model constructed from five optimal genes that could efficiently separate CAD patients from controls.

Conclusion

We identified several potential biomarkers for CAD and built a logistic regression model that will provide a valuable reference for future clinical diagnoses and guide therapeutic strategies.

Associations of the MTHFR rs1801133 polymorphism with gastric cancer risk in the Chinese Han population

In recent years, increasing evidence has implicated the importance of mutations in the MTHFR gene in the risk of gastric cancer risk. A single nucleotide polymorphism (SNP) in the MTHFR gene (rs1801133) may serve a critical role in gastric cancer. A hospital-based case-controlled study was performed to assess the risk of the rs1801133 polymorphism on gastric cancer. A total of 307 patients with gastric cancer and 560 patients in the control group were recruited. Genomic DNA was extracted from peripheral blood and genotyped for rs1801133 using the ligase detection reaction. The relationship between rs1801133 and gastric cancer risk was evaluated by unconditional logistical regression analysis. The rs1801133-TT genotype was associated with a borderline significantly decreased risk of gastric cancer [(TT vs. CC, adjusted odds ratio (OR)=0.54, 95% confidence intervals (CI)=0.35-0.83; P=0.006; CT vs. CC, adjusted OR=0.59, 95% CI=0.44-0.79, P<0.001; and TT/CT vs. CC, adjusted OR=0.61, 95% CI=0.44-0.83, P=0.001), and further analysis showed the relationship was evident amongst older patients and patients who never drank alcohol. The C>T mutation at rs1801133 of the MTHFR gene was associated with a decreased risk of gastric cancer in older individuals and those who never drink.

MTHFR rs1801133 Polymorphism Is Associated With Liver Fibrosis Progression in Chronic Hepatitis C: A Retrospective Study

Background: The MTHFR (methylenetetrahydrofolate reductase) rs1801133 polymorphism leads to higher circulating levels of homocysteine, which is related to several liver diseases. We aimed to evaluate the relationship between MTHFR rs1801133 polymorphism and liver fibrosis progression in HCV-infected patients. Methods: We conducted a preliminary retrospective cohort study in 208 non-cirrhotic HCV-infected patients. These subjects had at least two liver stiffness measurements (LSM), which were assessed using transient elastography, and no patient had cirrhosis at baseline. We analyzed the association between MTHFR rs1801133 and outcome variables using Generalized Linear Models. Results: HCV-infected patients were 47 years old, around 54% were males, a low frequency of high alcohol intake (13.5%) or prior use of intravenous drugs (10.1%). A total of 26 patients developed cirrhosis (LSM1 ≥ 12.5) during a median follow-up of 46.6 months. The presence of the rs1801133 C allele showed an inverse association with the LSM2/LSM1 ratio (adjusted AMR = 0.90; 95%CI = 0.83-0.98; p = 0.020) and the cirrhosis progression (adjusted OR = 0.43; 95%CI = 0.19-0.95; p = 0.038). Besides, rs1801133 CT/CC genotype had an inverse association with the LSM2/LSM1 ratio (adjusted AMR = 0.80; 95%CI = 0.68-0.95; p = 0.009) and the cirrhosis progression (adjusted OR= 0.21; 95%CI = 0.06-0.74; p = 0.015). Conclusions: MTHFR rs1801133 C allele carriers presented a diminished risk of liver fibrosis progression and development of cirrhosis than rs1801133 T allele carriers. This statement supports the hypothesis that MTHFR rs1801133 polymorphism appears to play a crucial role in chronic hepatitis C immunopathogenesis.

Effects of GST null genotypes on individual susceptibility to atherosclerotic cardiovascular diseases: a meta-analysis

Some genetic association studies tried to investigate potential associations between glutathione S-transferase (GST) null genotypes and atherosclerotic cardiovascular diseases (ASCVD). However, the results of these studies were not consistent. Thus, we performed the present meta-analysis to explore associations between GST null genotypes and ASCVD in a larger pooled population. Systematic literature research was performed in PubMed, Web of Science, and Embase to identify eligible studies. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) to estimate the strength of associations. Totally 47 studies were included for analyses. Pooled analyses suggested that GSTM1 (p = .007, OR = 1.29, 95%CI 1.07-1.56) and GSTP1 (p = .01, OR = 1.28, 95%CI 1.06-1.55) null genotypes were significantly associated with individual susceptibility to ASCVD in overall population. Further subgroup analyses revealed similar positive results for GSTM1 null genotype in South Asians and patients with coronary artery disease (CAD). No other significant results were observed for GST null genotypes in overall and subgroup analyses. In conclusion, our meta-analysis suggested that GSTM1 and GSTP1 null genotypes could impact individual susceptibility to ASCVD. These results suggested that these variations could be used to identify individuals at higher susceptibility to ASCVD.

GST null polymorphisms may affect the risk of coronary artery disease: evidence from a meta-analysis

Background

Whether glutathione S-transferase (GST) null polymorphisms, namely GSTM1 null, GSTP1 null and GSTT1 null polymorphisms, influence the risk of coronary artery disease (CAD) or not remains unclear. Thus, the authors performed a meta-analysis to more robustly estimate associations between GST null polymorphisms and the risk of CAD by integrating the results of previous publications.

Methods

Medline, Embase, Wanfang, VIP and CNKI were searched comprehensively for eligible studies, and 45 genetic association studies were finally selected to be included in this meta-analysis.

Results

We found that GSTM1 null polymorphism was significantly associated with the risk of CAD in overall population (OR = 1.37, p = 0.003) and mixed population (OR = 1.61, p = 0.004), GSTP1 null polymorphism was significantly associated with the risk of CAD in overall population (OR = 1.23, p = 0.03), whereas GSTT1 null polymorphism was significantly associated with the risk of CAD in overall population (OR = 1.23, p = 0.02), Caucasians (OR = 1.23, p = 0.02) and East Asians (OR = 1.38, p < 0.0001).

Conclusions

This meta-analysis demonstrated that GSTM1 null, GSTP1 null and GSTT1 null polymorphisms were all significantly associated with an increased risk of CAD.

Meta-analysis of the relationship between methylenetetrahydrofolate reductase C677T and A1298C polymorphism and venous thromboembolism in the Caucasian and Asian

Recent years, it is a highly debated topic that whether methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and A1298C polymorphism could increase susceptibility to venous thromboembolism (VTE) in the Asian and Caucasian. Therefore, we expect to settle that controversy evidentially. Basic methods: Electronic databases (Pubmed, embase, Cochrane library, scopus, OvidSP, Wiley Online library, Springer link, EBSCO, Elsevier Science Direct, Google scholar) without date limitation were searched. Crude odds ratio (OR) along with 95% confidence interval (95% CI) was calculated to assess the association quantitatively. Finally, a total of 37 eligible studies were included, containing 31 for MTHFR C677T polymorphism and 6 for MTHFR A1298C polymorphism. The pooled results suggested that MTHFR C677T mutation may increase susceptibility to VTE in reverse recessive model (CC+CT vs TT): OR = 0.68 (0.56, 0.83), reverse dominant model (CC vs CT +TT): OR = 0.82 (0.72, 0.94), heterozygote model (CT vs TT): OR = 0.65 (0.52, 0.81), homozygote model (CC vs TT): OR = 0.73 (0.60, 0.89) and allele model (C vs T): OR = 0.80 (0.71, 0.90). Subgroup analysis about Asian also support that results, but Caucasian group not. In addition, MTHFR A1298C polymorphism may be not related to VTE in all genetic model. The results of meta-analysis indicated that MTHFR C677T polymorphism might increase the risk of VTE, especially in Asian population.

Association of the methylene-tetrahydrofolate reductase gene rs1801133 C677T variant with serum homocysteine levels, and the severity of coronary artery disease

This study aimed to investigate whether the single nucleotide polymorphism C677T (rs1801133) of the methylene-tetrahydrofolate reductase (MTHFR) gene was associated with the risk of coronary artery disease (CAD) and circulating homocysteine (Hcy) levels in Tunisian population. 310 angiografically diagnosed CAD patients and 210 controls were enrolled in this study. The MTHFR C677T (rs1801133) polymorphism was genotyped, and the Hcy concentrations were measured. The severity of CAD was evaluated using the Gensini scoring system. Compared to the CC genotype, the TT genotype confers a higher risk for CAD severity with an OR = 9.07 and 95% CI = 3.78–21.8. The T allele was the predisposing allele for CAD and that it was probably associated with CAD severity. The area under the ROC curve for Hcy was 0.764 (95% CI 0.660 to 0.868, p = 0.001). The receiver operating characteristics curve (ROC) for Hcy showed its useful prediction of CAD. Hcy levels were not significantly associated with CAD severity expressed by Gensini Score (GS). The MTHFR C677T (rs1801133) polymorphism influences circulating Hcy levels. The MTHFR C677T polymorphism and hyperhomocysteinemia could have an important role in the prediction of the presence and not the severity expressed by GS of CAD.

Genetic and environmental factors associated with homocysteine concentrations in a population of healthy young adults. Analysis of the MAGNETIC study

BACKGROUND AND AIMS

Elevated homocysteine concentration is associated with a higher risk of cardiovascular disease. The aim of our study was to determine the environmental and genetic factors associated with serum homocysteine concentration in healthy young adults. Moreover, we aimed to determine the cutoff value of homocysteine concentration for predicting unfavorable MTHFR genotype and to investigate whether this association is modified by dietary patterns and serum folate status.

METHODS AND RESULTS

A total of 744 healthy individuals, aged 18-35 years, were included in the study. Diet quality was assessed by establishing diet quality scores and adherence to the pro-Healthy Diet Index (pHDI) and non-Healthy Diet Index (nHDI). Genotyping was performed using the TaqMan method. Multivariate analysis showed that pHDI, creatinine, folate concentrations, and the T/T genotype of the C677T polymorphism in MTHFR, as well as the interaction between the T/T genotype of MTHFR (C677T polymorphism) and folate level, were most strongly related to homocysteine concentrations. The specificity of a homocysteine >13.1 μmol/l in predicting T/T homozygous status was 76% (area under the curve 0.68).

CONCLUSION

Healthy dietary patterns, folate, and creatinine levels, as well as the C677T polymorphism, proved to be the strongest predictors of homocysteine concentrations. T/T genotype of MTHFR modifies the relationship between folate and homocysteine.

Combination of Exercise and Vegetarian Diet: Relationship with High Density-Lipoprotein Cholesterol in Taiwanese Adults Based on MTHFR rs1801133 Polymorphism

We examined the association between high-density lipoprotein cholesterol (HDL-C), and exercise and vegetarian diets, in Taiwanese adults, based on the Methylenetetrahydrofolate reductase (MTHFR) rs1801133 polymorphism. Using regression models, we analyzed historical data collected from 9255 Taiwan Biobank (TWB) participants from 2008 through 2015. Exposure to exercise was associated with higher HDL-C (β = 1.0508 and 1.4011 for GG and GA + AA individuals, respectively), whereas a vegetarian diet was associated with lower HDL-C (β = −6.2793 and −4.6359 for those with GG and GA + AA genotype, respectively). We found an interaction between exercise and diet among GG individuals (p = 0.0101). Compared with no exercise/no vegetarian diet, vegetarian diet/no exercise was associated with a 5.1514 mg/dl reduction in HDL-C among those with GG genotype (β = −5.1514, p < 0.0001) and a 4.8426 mg/dl reduction (β = −4.8426, p < 0.0001) among those with GA + AA genotype. Vegetarian diets in combination with exercise predicted a 6.5552 mg/dl reduction in HDL-C among GG individuals (β = −6.5552) and a 2.8668 mg/dl reduction among GA + AA individuals (p < 0.05). These findings demonstrated that vegetarian diet alone was associated with lower HDL-C, no matter the rs1801133 genotype. However, the inclusion of regular exercise predicted much lower levels among GG individuals, whereas levels among GA + AA individuals were relatively higher.

Genes and Eating Preferences, Their Roles in Personalized Nutrition

At present, personalized diets, which take into account consumer genetic characteristics, are growing popular. Nutrigenetics studies the effect of gene variations on metabolism and nutrigenomics, which branches off further and investigates how nutrients and food compounds affect genes. This work deals with the mutations affecting the assimilation of metabolites, contributing to nutrigenetic studies. We searched for the genes responsible for eating preferences which allow for the tailoring of personalized diets. Presently, genetic nutrition is growing in demand, as it contributes to the prevention and/or rehabilitation of non-communicable diseases, both monogenic and polygenic. In this work, we showed single-nucleotide polymorphisms in genes-missense mutations that change the functions of coded proteins, resulting in a particular eating preferences or a disease. We studied the genes influencing food preferences-particularly those responsible for fats and carbohydrates absorption, food intolerance, metabolism of vitamins, taste sensations, oxidation of xenobiotics, eating preferences and food addiction. As a result, 34 genes were identified that affect eating preferences. Significant shortcomings were found in the methods/programs for developing personalized diets that are used today, and the weaknesses were revealed in the development of nutrigenetics (inconsistency of data on SNP genes, ignoring population genetics data, difficult information to understand consumer, etc.). Taking into account all the shortcomings, an approximate model was proposed in the review for selecting an appropriate personalized diet. In the future, it is planned to develop the proposed model for the compilation of individual diets.

Genetic association between plasminogen activator inhibitor-1 rs1799889 polymorphism and venous thromboembolism: Evidence from a comprehensive meta-analysis

BACKGROUND

Association between plasminogen activator inhibitor-1 (PAI-1) rs1799889 polymorphism and venous thromboembolism (VTE) were explored by many previous studies, yet the findings of these studies were conflicting.

HYPOTHESIS

PAI-1 rs1799889 polymorphism may serve as a genetic marker of VTE. We aimed to better clarify the relationship between PAI-1 rs1799889 polymorphism and VTE in a larger combined population by performing a meta-analysis.

METHODS

Literatures were searched in Pubmed, Embase, Web of Science, and China National Knowledge Infrastructure (CNKI). We used Review Manager to combine the results of individual studies.

RESULTS

Forty-eight studies involving 14 806 participants were eligible for inclusion. Combined results revealed that PAI-1 rs1799889 polymorphism was significantly associated with VTE in Caucasians (dominant comparison: odds ratio [OR] 1.20, 95% confidence interval [CI] 1.09-1.32; recessive comparison: OR 0.84, 95% CI 0.76-0.94; allele comparison: OR 1.08, 95% CI 1.02-1.15) and East Asians (dominant comparison: OR 1.60, 95% CI 1.17-2.19; allele comparison: OR 1.53, 95% CI 1.21-1.93). Further analyses obtained similar significant associations in these with deep vein thrombosis (DVT) and these with Factor V Leiden mutation.

CONCLUSIONS

Our findings supported that PAI-1 rs1799889 polymorphism may serve as one of the predisposing factors of VTE in both Caucasians and East Asians, especially in these with DVT and these with Factor V Leiden mutation.

A meta-analysis of the relationship between VEGFR2 polymorphisms and atherosclerotic cardiovascular diseases

Background

Some previous studies explored associations between vascular endothelial growth factor receptor 2 (VEGFR2) polymorphisms and atherosclerotic cardiovascular diseases (ASCVD), with conflicting findings.

Hypothesis

We thought that VEGFR2 polymorphisms may influence susceptibility to ASCVD. Here, we aimed to better analyze the relationship between VEGFR2 polymorphisms and ASCVD in a larger combined population by performing a meta‐analysis.

Methods

We searched Pubmed, Embase, and Web of Science for related articles. We calculated odds ratio (OR) and 95% confidence interval (CI) to estimate whether there are genetic associations between VEGFR2 polymorphisms and ASCVD.

Results

Ten studies were included for this meta‐analysis (5474 cases and 8584 controls). VEGFR2 rs1870377 (dominant comparison: 0.81 (0.73‐0.89), I² = 56%; recessive comparison: 1.40 (1.25‐1.57), I² = 34%; allele comparison: 0.81 (0.76‐0.87), I² = 0%), rs2071559 (dominant comparison: 0.83 (0.76‐0.91), I² = 0%; recessive comparison: 1.22 (1.07‐1.38), I² = 0%; allele comparison: 0.86 (0.81‐0.92), I² = 0%) and rs2305948 (dominant comparison: 0.79 (0.72‐0.87), I² = 25%; recessive comparison: 1.44 (1.08‐1.92), I² = 60%; allele comparison: 0.79 (0.68‐0.92), I² = 73%) polymorphisms were all found to be significantly associated with susceptibility to ASCVD in general population. Subgroup analyses by type of disease revealed similar significant findings for rs1870377, rs2071559, and rs2305948 polymorphisms in coronary artery disease (CAD) subgroup. Besides, positive results were also found for rs1870377 polymorphism in ischemic stroke (IS) subgroup.

Conclusions

In summary, this meta‐analysis proved that these VEGFR2 polymorphisms could be used to identify individual with elevated susceptibility to ASCVD.

Methylene tetrahydrofolate reductase (MTHFR) gene rs1801133 C>T polymorphisms and response to 5-FU based chemotherapy in patients with colorectal cancer: a meta-analysis

Background: Methylene tetrahydrofolate reductase (MTHFR) catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a cosubstrate for homocysteine remethylation to methionine. Single nucleotide polymorphisms (SNP) of MTHF rs1801133 C>T can influence susceptibility to colorectal cancer. However, an association between MTHFR rs1801133 C>T polymorphisms and response to 5-Fluorouracil (5-FU) based chemotherapy in patients with colorectal cancer was not clear. Methods: Studies relevant to MTHFR rs1801133 C>T polymorphisms and response to 5-FU based chemotherapy in patients with colorectal cancer were systematic searched in the electronic databases of PubMed, Web of Science, Embase, and China National Knowledge Infrastructure (CNKI). The genotypes of CC, CT, and TT were extracted from each included publication. The genotypes CC, CT, and TT distribution in 5-FU based chemotherapy response and resistance groups were calculated and pooled through random or fixed effect model by the effect size of odds ratio (OR) and 95% confidence interval (95% CI). The publication bias was evaluated through Begg’s funnel plot and Egger’s line regression test. Results: After searching the electronic databases, 16 studies related to MTHFR gene rs1801133 C>T polymorphisms and a response to 5-FU based chemotherapy in patients with colorectal cancer were included in the present meta-analysis. The pooled data showed no statistical difference in tumor response rate between CT+TT and CC groups in the dominant genetic model CT+CC vs CC (OR=1.21, 95% CI: 0.93~1.59, p>0.05) and recessive model TT vs CT+CC (OR=1.37, 95% CI: 0.91~2.06, p>0.05). The grade 3-4 adverse reaction rate between CT+TT and CC groups also had no statistical difference in the dominant genetic model CT+CC vs CC (OR=0.90, 95% CI: 0.76~1.07, p>0.05) and recessive model TT vs CT+CC (OR=1.12, 95% CI: 0.84~1.50, p>0.05). The Begg’s funnel plot and Egger’s line regression test demonstrated no publication bias. Conclusion: The response and adverse reaction of 5-FU based chemotherapy in colorectal patients were not different in terms of MTHFR rs1801133 C>T polymorphisms.

A meta-analysis on relationship between paraoxonase 1 polymorphisms and atherosclerotic cardiovascular diseases

BACKGROUND

Some previous studies already explored associations between paraoxonase 1 (PON1) polymorphisms and atherosclerotic cardiovascular diseases (ASCVD), with conflicting findings. Here, we aimed to better analyze the relationship between PON1 polymorphisms and ASCVD in a larger combined population by performing a meta-analysis.

METHODS

We searched Pubmed, Embase and Web of Science for related articles. We calculated odds ratio (OR) and 95% confidence interval (CI) to estimate whether there are genetic associations between PON1 polymorphisms and ASCVD.

RESULTS

One hundred and nine studies were included for this meta-analysis. The PON1 rs854560 (17,220 cases and 18,570 controls, recessive comparison: OR = 0.83, 95%CI 0.72-0.96) and rs662 (30,717 cases and 54,894 controls, dominant comparison: OR = 0.82, 95% CI 0.77-0.89; recessive comparison: OR = 1.17, 95% CI 1.07-1.28; allele comparison: OR = 0.85, 95% CI 0.81-0.90) polymorphisms were both found to be significantly associated with susceptibility to ASCVD in general population. Subgroup analyses by ethnicity revealed similar significant findings for rs854560 polymorphism only in East Asians, while similar positive findings for rs662 polymorphism were observed in Caucasians, East Asians and South Asians. Subgroup analyses by type of disease indicated that the significant findings for rs854560 polymorphism were mainly driven by the ischemic stroke (IS) subgroup, whereas the positive results for rs662 polymorphism were mainly driven by the coronary artery disease (CAD) subgroup.

CONCLUSIONS

In summary, this meta-analysis proved that PON1 rs854560 polymorphism could be used to identify individual with elevated susceptibility to IS, whereas rs662 polymorphism could be used to identify individual with elevated susceptibility to CAD.